Method of making a structural unit



Jan. 30, 1934. w. McQUADE METHOD OF MAKING A STRUCTURAL UNIT Filed April 11, 1932 INVENTOR Vl/alter M Quade BY 94 W A TTQRNEY UNITED STATES PATENTVOFFICE METHOD OF MAKING A STRUCTURAL UNIT Walter McQuade, Port Washington, N. Y., as-

signor to Johns-Manville Corporation, New York, N. Y., a corporation of New York Application April 11, 1932. Serial No. 604,532 17 Claims. (CI. 18-48) This invention relates to a method of making of an appa a us suitable for use in th manufa a unit of structural material of uneven surface, u of the products of t e inventionparticularly a rigid shingle with an irregularly 2 is a perspective V w Of the a y d corrugated surface. The invention pertains es- Provided W a molding Su face a ap d to pecially to making such shingles from a composip rt n irr gular urfac to th r i y deform- 60 tion, such as one containing a hydraulic cementiable mixture of. Portland cement and asbestos tious material and asbestos fibers, that is plastic rs.

or readily deformable at one stage of the process s- 3 t0 6 inclusive ar and V w of Segments of manufacturing t shing33s of the sheet material as it travels along the con- The invention provides a means of making Veyor and illustrate the condition of Sheet Ob- 65 elevations and depressions f ing ornamental taining at the stages indicated by the positions of contours in the surface of mixed raw materials the.seveml lines t on Figs. '7 and 8 are a perspective and a sectional while in the readily deformable state and protect- View on Mn 8 8 f 7 1 of a ing these irregularities against substantial ded .g '2 a W m formation or obliteration during subsequent i fi gf 'm treatment.1 A typical procedure involves fgrmingf g g i iig g g a g g l z the irregu arities or depressions in a sur ace 0 the material, covering them with a filler material hydraltllhc cgmentltlgus m g Such i g' g that is removable without change of state, then 22222 53; g is gggt g gl gigg i s; densiifying and ardening. the material and reveyor 12. picker roll 13 of a convention; type 22335 2 filhng mammal Subsequent to the serves to brush off excess material and leaves the Rigid shingles prepared from a mixture of .9 band comprismgthe mixftlre of ce- Portland cement and asbestos fibers, either in mentltlous and fibrous m gmergmg i or by machiee a are and a 2231; it? i titt stfit ttiii'ii is fettii; :lmflar to that descnbed in Patent. 979548 deformable. It passes between side guides (not 0 Norton, dated December 27, 1910, are illustrashown) to true up the edges The Sheet is next t the products and matena1s 9 which the subjected to the action of the rotary die 14 promvention has been successfully applied, and the vided with a moldin gurface which im resses invention is specifically described hereinafter with the desired pattern ffomamental contour: suit referepce such produpts' Such shmgles may ably irregular corrugations, on the sheet and, at contain various proportions of Portland cement the same time Slightly compresses the material to w asbestos fibers tjor example to and makes it more dense below the depressions Smtably parts by Welght of the cement than elsewhere Die 14 shown in detail in Fig to 1 part of asbestos. Also, the shingles may con- 2 is specially adapted for the production tain admixed coloring material, such as lamp Shingles, such as illustrated in Figs and 8 black for eXamp1e-and/r a "eneer of coloring wherein the ornamental contours or surface ir: materials Such as pigments adhered to a face regularities are confined to the portion of the of the shmgle by means of cementltlous shingle exposed to view when laid in a finished 40 terial. Thus a veneer of Portland cement and Structural assembly, Such as a root The pattern burnt-umber, chrome green yellow oxide and/or illustrated imparts to a portion of the face of the the like, may be applied to the top Surface of a shingle an irregular grooved surface simulating band Sheet of the mixture of the other shingle the weathered and antique efiects obtained in old I ingredients, Wetted with a Spray of Water, and wooden shingles and timbers. Also, .the shingle. firmly adhered to the said band or sheet, as by may be colored, by conventional means at some subseque pressing and hardening operationsstage in the manufacture, with materials that Further, a surface coating 0f colored material, impart a color resembling weathered wood to all such as granulated colored slate or tile, m y be of the shingle or, preferably, only to the surface sprinkled over the top surface and welded thereto of the shingle that is to be exposed in a struc- 105 by subsequent pressing and hardening. tural assembly.

My improved products, as well as a method Die 14 and picker roll 13 are rotated by any of producing them, are illustrated in the accomusual means, such as belts 15 from pulley 16. panying drawing in which The sheet next passes under a water spray 21 Fig. 1 illustrates diagrammatically an assembly of the usual type for applying suflicient water no to the sheet to hydrate the cement, the water thus applied being quickly absorbed in the porous mass.

The sheet then passes under a vessel 22 containing a suitable filler material and provided with a hopper or sieve 23 for feeding the filler material 27 into the depressions in the sheet formed by die 14.

The filling material which is preferred at this time is granulated rubber. Thus, used, solid rubber, truck tires may be cut or granulated to a form suitable for use as the granular filler. I have used to advantage such granulated rubber having particles of such size that most, suitably all, of them pass through a B-mesh screen but are retained on a 28-mesh screen, in a standard screening test. Thus, I have used granulated vulcanized rubber that shows no particles retained on a 3- mesh screen, 14 to 24 per cent by weight of particles retained on a G-mesh screen, and 4 to 7 per cent through a 28-mesh screen, in a test in which the screens were vibrated.

The feed of the filler material from the hopper may be produced by vibrating the container 22 or by other conventional means. Apron 24 serves to level off the filler material in such a manner that it covers the corrugated surface, as illustrated in Fig. 5.

The sheet with the surface thus treated next passes under a compression roll 25 which partially compacts the sheet to the degree indicated in Fig. 6. Both compression roll 25 and die 14 may be arranged with their axes at a slight angle with respect to the plane of the conveyor 12, so that sheet 11 is thereby tapered in a transverse direction, the thick butt portion coinciding with the ornamental surface, as indicated in Fig. 8.

The sheet is then severed by crosswise cutting into segments, which are usually somewhat larger than the size desired for the finished shingle. The segments are stacked in piles with a flat metal plate between adjacent segments and subjected to further compression or densifying in a hydraulic press. During this pressing, the ornamental contours may be deformed slightly but not excessively; the finished sheet still shows pronounced elevations and depressions, as described later. The compacted segments are removed from the press and are permitted to stand until the cement is thoroughly hardened, the metal plates being removed after the cement has taken an initial set. These operations are not shown, since they are conventional in the manufacture of shingles of the rigid asbestos type.

The filler material is then removed from the hardened product by brushing, for example, or by other mechanical means not involving liquefaction or change of state. The segments thus treated are ordinarily somewhat wider than the width of two shingles and are finally divided and trimmed to size, to produce individual shingles such as illustrated in Figs. 7 and 8. The butt end edge 26 may-be left untrimmed, of rough and uneven shape. Nail holes 28 are provided.

Another product and process to which the present invention is applicable as an improvement are described in U. S. Patent 1,513,620 to MacIldowie; According to MacIldowie, granules of rock salt, or other liquefiable material, are spread upon a plastic sheet of Portland cement, asbestos fibers, and water, for example, and impressed therein, the sheet hardened, and the granules removed from the surface by liquefaction, as by dissolving in a solvent.

In my improved process, the liquefiable material of MacIldowie is replaced by granular rubber or the like, with substantial improvement in the process as well as a change in the product.

The ease of substantialbut not complete deformation of rubber under pressure makes possible the application of high pressure, say 14,000 pounds per square inch of the plastic sheet coated with such material, without embedding the granular rubber to an undesired depth in the said sheet. Under such pressure the rubber tends to flatten. When the pressure is released, the rubber, being resilient, resumes its original shape. In so doing, it loosens itself from the relatively wide, shallow pits formed during the compression and can be brushed therefrom. The readiness with which the brushing out of the rubber filler is accomplished is further facilitated by the ability of the rubber to be stretched or deformed by the brushing.

When non-resilient granules are used, on the other hand, either the granule is pushed relatively far into the plastic sheet, if the granule is hard, or the granule is crushed, if it is soft. Thus, the pits formed in a plastic sheet by granulated stone or rock salt may be undesirably deep; those formed by a wax, such as parafiin, may be very shallow and almost invisible.

Furthermore, granular rubber, after being brushed from a pressed sheet may be reused directly. A material removed by liquefaction, say by solution, is not directly reusable. In fact, recovery of such material for reuse is sometimes too inconvenient to be economically desirable. Thus, salt used as the granular material may be completely lost, the salt dissolved out bywashing involving an unjustified expense of recovery, and being preferably replaced by new salt.

In addition, a water-soluble filler such as salt, if used,'dissolves in the water in the sheet. First, this affects the setting of the cementin the sheet, particularly in the surface adjacent to the salt. Second, the presence of water-soluble material in the finished product, after the final washing, may cause an undesired amount of blooming or efllorescence, that is, migration of soluble material to the surface of the product.

Also, granular rubber may consist of very irregularly shaped particles, some of them more or less stringy, for example. This irregularity favors irregularity of pits formed in the surface of the plastic material pressed against the particles.

Since rubber is impermeable to water, the-rubber does not become bonded to the plastic sheet by penetration of the aqueous composition of the sheet into the rubber.

Granulated cork may be, used as the filler,

to protect irregularities in a plastic sheet against,

excessive deformation during pressing or to produce pitting of an otherwise smooth surface. However, cork is more diflicult to remove from the pressed sheet, possibly because of a lesser degree of resilience and a somewhat greater permeability to water than possessed by rubber. Sawdust, used as the filler, is more diflicultly removable than the cork.

While the invention has been described with particular reference to the provision of omamental contours or irregularities in structural units or shingles such as those known commercially as rigid asbestos shingles, the invention is applicable generally to the provision of ornamental contours in materials which are readily deformable at one stage of their manufacture and are subsequently hardened. While irregumaterial and proceeding otherwise as described above.

The term plastic is used herein as synonymous and co-extensive in meaning with the term readily deformable and does 'not imply that the material so characterized necessarily possesses a self-sustaining structure, since the preferred material for the application of our invention is a dry mixture of Portland cement and asbestos which, although readiy deformable, is not sufiiciently coherent to be self-sustaining.

Since the details that have been given are for the purpose of illustration and not restriction of the invention, it is intended that the invention should be limited only by the terms of the claims.

What I claim is:

1. A method of imparting a surface having ornamental contours to materials which are plastic or readily deformable in one stage of their manufacture and which are subsequently densified by application of pressure, comprising treating the material while in the readily deformable stage to impart the desired elevations and depressions forming the ornamental contours in the surface thereof, filling the depressions with a granular, resilient filling material, applying pressure to the surface of the plastic material thus treated, to impart the requisite degree of density and strength thereto and to impress the filling material in part into the surface of the sheet, and thereafter removing the filling material from the depressions, to expose pits formed by impressing and then remov-' ing the filling material and also the ornamental contours.

2. A method of imparting a surface having ornamental contours to sheet material which is readily deformable or plastic at one stage of its manufacture which comprises passing an elongated sheet or strip of the material while in its plastic state into contact with a molding surface adapted to mold depressions and elevations, forming the desired ornamental contours in the surface of the sheet, filling the depressions with a granular, water-insoluble, resilient filling material, applying pressure to the surface of the plastic sheet thus treated to densify and strengthen the sheet, and thereafter removing the filling material to expose the ornamental contours.

3. A method of manufacturing fiat shapes such as sheets, slabs, and the like, having ornamental contours on the surface thereof and adapted for use as shingles and other purposes, from hydraulic cementitious material, which comprises passing an elongated strip or sheet of the cemen titious material into contact with a molding surface adaptcd to mold depressions and elevations, forming the desired ornamental contours in the surface of the sheet, filling the depressions with a granular, resilient filling material, subjecting the surface thus treated to pressure to densify the sheet, allowing the densified sheet to Harden, and thereafter removing the filling material to expose the ornamental contours.

4. A method of manufacturing fiat shapes such as sheets, slabs, and the like, having ornamental contours on the surface thereof and adapted for use as shingles and other purposes, from hydraulic cementitious material and a reenforcing fibrous material, which comprises passing an elongated strip or sheet of the cementitious material and the fibrous material into contact with a molding surface adapted to partially compress the sheet and simultaneously mold depressions and elevations forming the desired ornamental contours in the surface of the sheet, filling the depressions with a granular, resilient filling material, subjecting the surface thus treated to pressure to densify the sheet, allowing the densified sheet to harden, and thereafter removing the filling material to expose the ornamental contours.

5. A method of manufacturing fiat shapes such as sheets, slabs, and the like, having ornamental contours on the surface thereof and adapted for use as shingles and other purposes, from hydraulic cementitious material, which comprises passing an elongated strip or sheet of dry, finely divided cementitious material into contact with a molding surface adapted to mold depressions and elevations forming the desired ornamental contours in the surface of the sheet, spraying sufiicient water upon the surface of the sheet to hydrate the cementitious material, filling the depressions with a granular, resilient filling ma terial, subjecting the surface thus treated to pressure to densify the sheet, allowing the densified sheet to harden, and thereafter removing the filling material to expose the ornamental contours.

'6. A method of manufacturing rigid shingles which comprises passing a layer consisting chief 1y of a mixture of'Portland cement and fibrous material into contact with a mrding surface adapted to mold depressions and elevations form-- ing the desired ornamental contours in the surface of the layer, filling the depressions with a granular, resilient filling material, subjecting the surface thus treated to pressure, cutting the compacted material into shingles and removing the filling material.

7. A method of manufacturing rigid shingles which comprises passing a layer, consisting chiefly of a mixture of approximately 1.9 parts by weight of Portland cement and 1 part of asbestos fibers and admixed coloring material to establish the desired color, into contact with a molding surface adapted to mold depressions and elevations forming the desired ornamental contours in the surface of the layer, filling the depressions with a granular, resilient filling material, subjecting the surface thus treated to pressure, cutting the compacted material into shingles, and removing the filling material.

8. In the process of manufacture of a shingle from a mixture consisting chiefly of Portland cement and asbestos fibers, the improvement comprising forming the mixture into a sheet, irregularly corrugating a portion of a face of the sheet, covering the corrugated face with waterinsoluble, granular filling material, compressing and hardening the covered sheet, and then removing the filling material from the sheet without change of state, whereby there is produced .cement and asbestos fibers, the improvement comprising forming the mixture into a sheet, corrugating a portion of a face of the sheet,

covering the corrugated face with water-insoluble, granular, water-impermeable filling material, compressing and hardening the covered sheet, and then removing the filling material from the sheet, whereby there is produced a rigid shingle provided with a face of modified.

.light-refiecting properties.

a rigid shingle provided with a face of modifie light-reflecting properties.

11. In the process of manufacture of a. shingle from a. mixture consisting chiefly of Portland cement and asbestos fibers, the improvement comprising forming the mixture into a sheet, corrugating a portion of a face of the sheet, covering the corrugated'face with granularrubber filling material, compressing and hardening the covered sheet, and then removing the filling material from the sheet, whereby-there is produced a rigid shingle provided with a face of modified light-reflecting properties. i

12. In the process of manufacture of a shingle from a mixture consisting chiefiy of Portland cement and asbestos fibers, the improvement comprising forming the'mixture into a sheet, corrugating a portion of a face of the sheet, covering the corrugated face with granular cork filling material, compressing and hardening the covered sheet, and then removing the filling material from the sheet, whereby there is produced a rigid shingle provided with a face of modified light-reflecting properties.

13. In the process of manufacture of a shingle from a mixture consisting'chiefiy of Portland cement and asbestos fibers, the improvement comprising forming the mixture into a sheet, irregularly corrugating a portion of a face of the sheet, covering the corrugated face with water-insoluble, granular filling material of irregularly shaped particles, compressing and hardening the covered sheet, and then removing the filling material from the sheet, whereby there is produced a rigid shingle provided with a face of modified light-reflecting properties.

14. In the process of manufacture of a shingle from a mixture consisting chiefly of Portland cement and asbestos fibers, the improvement com- 0 prising forming the mixture into a sheet, irregularly corruga'ting a portion of a face of the sheet, covering the corrugated face with water-insoluble, granular resilient filling material of size of particles suiiiciently small to pass a 3-mesh 5 screen,'compressing and hardening the. covered sheet, and then removing the filling material from the sheet, whereby there is produced a rigid shingle provided with a'face of modified lightrefiecting properties. 7

15. In the manufacture of a shingle consisting chiefly of a mixture of Portland cement and asbestos fibers and adapted for use in a structural assembly, the method which comprises making the said mixture into a sheet, adding a coloring 5 material to the portion of the sheet that is to constitute the exposed face of the shingle in a structural assembly, impressing irregular corrugations upon the said portion of the sheet, covering the corrugated sheet with granular rubber filling material or the like to protect the corrugations from excessive deformation, compressing and hardening the covered article, and then removing the filling material, whereby a rigid shingle resembling weathered wood in appearance is produced.

16. In the manufacture of sheets from a mixture that is deformable at one stage of the manufacture, the method which comprises forming a deformable sheet, spreading thereon granular, re-. silient material, compressing and hardening the sheet in contact with the resilient material, and then removing the said resilient material from the hardened sheet.

17. In the manufacture of sheets from a mixture that is deformable at one stage of the manufacture, the method which comprises forming a deformable sheet, spreading thereon granular rubber, compressing and hardening the sheet in contact with the rubber, and then removing the rubber from the hardened sheet without change 120 of state.

WALTER. McQUADE. 

